[KYLIN-4158] Query failed for GroupBy an expression of column with limit in SQL

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: v2.6.2
• Fix Version/s: v3.0.0-beta, v2.6.4
• Component/s: Query Engine
• Assignee: PENG Zhengshuai
• Reporter: PENG Zhengshuai
• Created: 05/Sep/19 08:55
• Updated: 13/Oct/19 00:37
• Resolved: 18/Sep/19 03:29

Description

When executing a sql query, the limit should not be pushdown to storage scan level if group by clause is an expression of columns.

For example:

SELECT (CASE WHEN ("TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" IN ('Auction', 'FP-GTC')) THEN 'Auction' ELSE "TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" END) AS "LSTG_FORMAT_NAME__group_",
  SUM("TEST_KYLIN_FACT"."PRICE") AS "sum_PRICE_ok"
FROM "TEST_KYLIN_FACT" "TEST_KYLIN_FACT"
GROUP BY (CASE WHEN ("TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" IN ('Auction', 'FP-GTC')) THEN 'Auction' ELSE "TEST_KYLIN_FACT"."LSTG_FORMAT_NAME" END)
limit 4

In this SQL, group by clause is an expression, the limit should NOT be push-down to storage scan level, otherwise, the result is incorrect

Issue Links

• links to: GitHub Pull Request #827